1. Field of the Invention
The present invention generally relates to a cylinder sleeve assembly used in a cylinder block for a multi-cylinder internal combustion engine, and more particularly, a cylinder sleeve assembly cast in a cylinder barrel assembly in a cylinder block for a multi-cylinder internal combustion engine, and a mold for use in production of sand mold for casting the cylinder sleeve assembly.
2. Description of the Prior Art
There is such a conventionally known cylinder sleeve assembly including a plurality of circumferentially extending convexities arranged at predetermined distances along a generating line (see Japanese Patent Application Laid-open No. 104740/80).
One of reasons why the convexities are provided is that the contact area of the cylinder sleeve assembly is increased to enhance the adhesion of the cylinder sleeve assembly with respect to the cylinder barrel assembly. However, the convexities do not contribute to the enhancement of the adhesion of the cylinder sleeve assembly to the cylinder barrel assembly in a particular area which will be described below.
That is, if adjacent cylindrical peripheral walls of a plurality of cylinder sleeves are coupled to each other as described above, an outer peripheral surface of the cylinder sleeve assembly has valley-like areas on opposite sides of a coupled portion between the adjacent cylindrical peripheral walls.
In a mold for casting a cylinder block having a cylinder sleeve assembly of such a construction placed therein, if a molten metal is poured into a cylinder barrel assembly molding cavity defined between the cylinder sleeve assembly and a water jacket shaping core, the molten metal located a region faced by the valley-like areas tends to be solidified more slowly than the molten metal located at the other region. For this reason, a circumferential solidification/shrinkage force is applied to a valley-like area-opposed portion of the cylinder barrel assembly. However, the above-described convexities cannot oppose such solidification/shrinkage force and hence, sink marks are generated on the valley-like area-opposed portion, resulting in a deteriorated adhesion between the opposed portion and the valley-like area.